Sealing arrangement

ABSTRACT

In a sealing arrangement, in particular for the connection of a manifold to a cylinder head of an internal combustion engine, with a flat support ( 1, 3 ) and at least one sealing element in the form of a ring element ( 17 ) that forms a mold seal, a support ( 1, 3 ) and a ring element ( 17 ) form a unit that holds the latter captively on the support ( 1, 3 ).

The invention relates to a sealing arrangement, in particular for the connection of a manifold to a cylinder head of an internal combustion engine, with a flat support and at least one sealing element in the form of a ring element that forms a mold seal.

Sealing arrangements of this type are widely used for the connection of exhaust-gas-carrying pipes to cylinder heads of internal combustion engines. Based on the high exhaust gas temperatures that occur, both flat supports of the sealing arrangement and the respective ring element are metallic components with smaller wall thickness in each case, the ring element usually having a profiled configuration.

In a disadvantageous way, the assembly process of such multi-part sealing arrangements is configured in a comparatively complicated manner, since during production of the connection with the cylinder head, care must be taken that the ring element is actually present and correctly positioned between the respective connecting parts.

With respect to this prior art, the object of the invention is to make available a sealing arrangement, which is provided in particular for the connection of a manifold to a cylinder head of an internal combustion engine, in which the assembly process can be performed comparatively more simply and more safely.

According to the invention, this object is achieved by a sealing arrangement that has the features of claim 1 in its entirety.

Since the sealing arrangement according to the invention forms a unit that captively contains the respective ring element, the entire operating sequence is configured in an especially simple and safe manner during use since neither during the supply of the sealing arrangements in the actual assembly position, which takes place in an automated fashion in industrial manufacturing, nor in the actual connecting process must it be ensured whether or not the respective ring element is present and correctly positioned.

In advantageous embodiments in which the support has a flat plate with at least one opening for a gas flow, preferably an exhaust gas flow, the ring element extends along the edge of the respective opening.

By preference, the ring element that forms the mold seal has the shape of a C-profile that is opened radially outward and is raised from the plane of the plate. In this connection, the arrangement can be designed such that the end area of the C-profile that is adjacent to the plane of the plate forms a slight curvature on the side of the plate that is set against the end of the C-profile that is raised from the plane.

Provision can be made in this instance in an especially advantageous way so that the ring element is formed by the edge of the opening that is integral with the plate and that is raised from the plane of the plate. The ring element or elements therefore forms/form an integral component of the plate.

In the production of such embodiments, the procedure may be that by piercing the plate, first the opening or openings is/are formed, the respective opening edge is then raised and is thereafter turned over outward by applying pressing force to form the C-profile. In such a pressing or molding process, the lower end area of the C-profile that interconnects with the plate can form a slight curvature on the side of the plate that is opposite the end of the C-profile that is raised from the plane. Such examples are characterized by an especially good sealing action.

When the ring element does not form any integral component of the plate, but rather is a separate component, the arrangement can be designed such that a holding device that produces a frictional connection between plate and ring element is provided to secure the latter captively to the plate.

In this connection, in advantageous embodiments, retaining collars that project slightly radially outward are molded onto the edge of the C-profile that is opposite the edge of the ring element that is raised from the plane of the plate, said projections flexibly deforming radially inward in the plate's respective opening when the ring element is attached, thereby creating a frictional connection; the effect of this is to generate a holding force.

In the way conventional in sealing arrangements for the connection of exhaust gas manifolds, the plate can have several openings, arranged at a distance from one another, for the passage of a respective exhaust gas flow. For example, the plate can have the shape of a so-called gland with two plate areas, in which one opening each is provided and which are connected to one another by a plate arm that has a smaller width compared to these plate areas.

To promote a thermal decoupling between cylinder head and the hot exhaust gas manifold, the plate preferably has openings that are divided around the respective openings for gas flows, whereby round holes or crescent-shaped holes can be provided that surround the respective openings.

Below, the invention will be explained in detail based on the embodiments depicted in the drawing. Here:

FIG. 1 shows a top view of the sealing arrangement according to the invention in the form of a so-called gland for use in the attachment connection between an exhaust gas manifold and a cylinder head, different embodiments being shown on the right side and the left side in the figure, in which differently molded openings for a thermal decoupling are provided;

FIG. 2 shows a section corresponding to line II-II in FIG. 1;

FIG. 3 shows a partial-section view in which the area referred to as III in FIG. 2 is depicted greatly enlarged;

FIG. 4 shows a top view of the ring element, used as a sealing element, of another embodiment of the sealing arrangement according to the invention;

FIG. 5 shows a greatly enlarged detail view of the area that is referred to as V in FIG. 4;

FIG. 6 shows a partial cross-section of the ring element of FIG. 4, greatly enlarged compared to FIG. 4 and drawn in cutaway, and the associated edge section of the opening of a plate, the condition before attaching the ring element on the plate being shown, and

FIG. 7 shows a view that corresponds to FIG. 6, the ring element being shown after the plate is inserted into the opening.

The invention will be explained in greater detail below on the basis of examples, in which the sealing arrangement has the shape of a so-called gland, a flat metal plate that forms the support of the sealing arrangement having two plate areas 1 and 3 that are integrally connected together via a comparatively narrow plate arm 5, the arm 5 connecting the central areas of the plate areas 1 and 3 to one another and extending along the longitudinal axis 7 of the sealing arrangement. With the center of the circle 9 located on the longitudinal axis 7, there is a circular opening 11 for the passage of an exhaust gas flow, which emerges from a respective exhaust opening of a cylinder head (not shown), in each plate area 1 and 3. Screw holes 13 that are located in two plate areas 1 and 3 are provided for fastening screws, which attach the manifold, not shown, and the sealing arrangement to the cylinder head.

In addition to the screw holes 13, holes 15, which aim at a reduction of the heat-conducting surface of the sealing arrangement and thus a thermal decoupling between cylinder head and exhaust gas manifold, are located in the plate areas 1 and 3. In FIG. 1, two different embodiments are illustrated for the holes 15; specifically crescent-shaped holes 15 are provided in the plate area 1 on the left, while holes 15 in the form of round holes are provided in the plate area 3 on the right.

FIGS. 1 to 3 relate to an embodiment in which for each opening 11, a sealing element that forms a component of the sealing arrangement is formed by a ring element 17, which is integrally formed with the respective plate area 1 and 3 in each case, such that the opening edge is raised on the respective opening 11 of the opening edge. To form a C-profile 19, the end area of the raised edge is turned radially outward by means of applying a compressive or pressing force to form the profile shape that is clearly shown in FIG. 3. By this shaping, a slight curvature 23 is produced on the side of the plate areas 1, 3 that is opposite the raised end 21 of the C-profile 19, and said curvature on this side of the plate areas 1, 3 forms a flat layer crimp that projects relative to and extends around the latter. The curvature 23 projects by 0.5 to 3, preferably by 1 sheet-metal thickness of the plate relative to the areas 1, 3 thereof.

Based on FIGS. 4 to 7, another embodiment is explained, in which instead of the above-described ring element 17, which is integral with the respective plate area 1, 3, a separate metal ring element 25 is provided, which also has the shape of a C-profile 19. As is the case in the plate with the plate areas 1 and 3, the ring element 25 is also a thin-walled metal component whose wall thickness, as is the case with the plate, is, for example, in the range of 0.3 mm. For a captive attachment of the ring element 25 on the respective opening 11 in the associated plate area 1, 3, the ring element 25 has three retaining collars 27 on the profile edge that is opposite its outer end 21, and said retaining collars are distributed uniformly on the periphery of the ring element 25, see FIG. 4. As shown most clearly by the enlarged view of FIG. 5, the retaining collars 27 in (undeformed) initial condition form claw-like projections that project slightly radially on the respective peripheral edge 26 of the ring element 25.

FIG. 6 shows the initial condition shortly before the application of the ring element 25 on the edge of the opening 11 of the respective plate area 1, 3, it being apparent that the retaining collars 27 extend slightly radially outward over the edge of the opening 11. If the ring element is forced into the opening 11 by applying a compressive force corresponding to the force arrow 29, a flexible deformation of the retaining collars 27 occurs when pressing into the opening 11, see FIG. 7, by which a frictional connection, which acts as a holding force, is produced on the opening 11, by which the ring element 25 is held captively on the opening 11, and the free ends of the retaining collars 27 in each case being supported flush with the inside wall or inside edge that delineates the opening 11. Based on the oblique arrangement of the retaining collars 27, the outside corner edges (cf. FIG. 7) of the latter come into linear contact with the inside wall of the opening 11 relative to the plate areas 1, 3, so that in this respect, a very high edge pressing force takes place, which makes it possible to mount the ring element 25 securely in the opening 11 of the plate despite the flexing of the retaining collars 27, but which can also be easily detached for repair purposes.

In this respect, the ring element 25 can be easily replaced with a new part. Additionally, with inclusion of common manufacturing tolerances, the respective retaining collar arrangement of three retaining collars 27 allows a very exact hub centering of the ring element 25 in the opening 11 to effect in such a way a reliable sealing system. The retaining collars 27 preferably wind up at a steep oblique angle resting on the external edge of the free opening 11.

The ring element 25 can be slightly deformed in a similar way on its peripheral edge 26 that has the retaining collars 27 by the compressive forces that are exerted when it is depressed, as is shown in FIG. 3 for the ring element 17, where a slight curvature 23 is produced by the compressive force that forms the C-profile 19 below the plate 1, 3. FIG. 7 therefore also shows a corresponding curvature 23 for the ring element 25 on its edge opposite the profile end 21 (peripheral edge 26 in FIG. 5). The respective retaining collar 27 extends from this curvature 23 in an oblique support angle of between 30° to 60°, preferably about 45°, in the inside edge of the opening 11, by which the curvature 23 is supported and is held in its sealing position, which improves the sealing in this respect.

To enhance this supporting action, as FIG. 5 shows, the respective retaining collar 27 in the C-profile 19 is provided on both sides with one recess each, which forms an indentation in the adjacent profile wall, which helps to further improve the flexible holding action for the individual retaining collar 27. Moreover, at a buckling point (FIG. 7), the arc-shaped profile 19 that is shown in cross-section (FIG. 6) undergoes transition into the retaining collar 27 that runs at an oblique angle and is straight at this point, the buckling point being arranged in a virtual vertical extension below the free profile end of the C-profile 19 that is located above it.

Furthermore, the term “sealing ring or mold” also extends to ring embodiments with oval shape or those with a rectangular design, preferably the corners of the rectangle being designed in a rounded way. Other ring forms are possible here. For this purpose, the respective images of the mold or sealing ring preferably follow the respective geometry thereof. 

1. Sealing arrangement, in particular for the connection of a manifold to a cylinder head of an internal combustion engine, with a flat support (1, 3) and at least one sealing element in the form of a ring element (17; 25) that forms a mold seal, characterized in that the support (1, 3) and the ring element (17; 25) form a unit that holds the latter captively on the support.
 2. The sealing arrangement according to claim 1, wherein the support has a flat plate (1, 3) with at least one opening (11) for a gas flow, preferably an exhaust gas flow, and wherein the ring element (17; 25) extends along the edge of the respective opening (11).
 3. The sealing arrangement according to claim 1 or 2, wherein the respective ring element (17; 25) has the shape of a C-profile (19) that is opened radially outward and is raised from the plane of the plate (1, 3).
 4. The sealing arrangement according to one of claims 1 to 3, wherein the end area of the C-profile (19) that is adjacent to the plane of the plate (1, 3) forms a slight curvature (23) on the side of the plate (1, 3) that is opposite the end (21) of the C-profile (19) that is raised from the plane.
 5. The sealing arrangement according to claim 2, wherein the ring element (17) is formed by the edge of the respective opening (11) that is integral with the plate (1, 3) and is raised from the plane of the plate (1, 3).
 6. The sealing arrangement according to one of claims 1 to 4, wherein a holding device (27) that produces a frictional connection between plate (1, 3) and ring element (25) is provided to secure the latter captively to the plate (1, 3).
 7. The sealing arrangement according to claim 6, wherein retaining collars (27) that project slightly radially outward are molded onto the edge of the C-profile (19) that is opposite the edge of the ring element (25) that is raised from the plane of the plate, said projections flexibly deforming radially inward in the plate's (1, 3) respective opening (11) when the ring element (25) is attached, thereby creating a frictional connection.
 8. The sealing arrangement according to one of claims 1 to 7, wherein the plate (1, 3) has several openings (11), arranged at a distance from one another, for the passage of a respective gas flow.
 9. The sealing arrangement according to claim 8, wherein the plate has the shape of a so-called gland with two plate areas (1, 3), in which one opening (11) each is provided, and which are connected to one another by a plate arm (5) that has a smaller width compared to these plate areas (1, 3).
 10. The sealing arrangement according to one of claims 1 to 9, wherein the plate has holes (15) that are distributed around the respective openings (11) for gas flows.
 11. The sealing arrangement according to claim 10, wherein holes (15) surrounding the respective crescent-shaped openings (11) are present. 